This invention relates to a runoff rain gauge, and more particularly to a rain gauge that can provide an estimate of the rainfall split between soil infiltration and runoff.
Runoff rain gauges are known from applicant's earlier U.S. Pat. No. 7,066,021 and US 20060191333 which are hereby incorporated herein by reference. These runoff rain gauges may require extraction of a core soil sample from the ground, which can introduce inaccuracy in some conditions by disturbing the original conditions of the soil infiltration sample.
Earlier runoff rain gauge designs for a runoff rain gauge stored collected precipitation directly on top of the core sample. Some of the stored water typically infiltrated into the core sample. The remainder flowed via gravity through the runoff circuit to a runoff-measuring device. For the prior in situ design, this may require mounting the runoff-measuring device below grade to allow for gravity flow. However, a self-draining gauge mounted below grade cannot discharge to grade without the use of a pump, which made the use of an electronic gauge for the in situ format problematic. There is a need in the art for a design that can combine the advantages of the in situ format with the convenience of a self-draining gauge for measuring runoff.